Metallographic cooling rates of group IIF iron meteorites
نویسندگان
چکیده
منابع مشابه
Metallographic cooling rates of the IIIAB iron meteorites
An improved computer simulation program has been developed and used to re-measure the metallographic cooling rates of the IIIAB irons, the largest iron meteorite chemical group. The formation of this chemical group is attributed to fractional crystallization of a single molten metallic core during solidification. Group IIIAB irons cooling rates vary by a factor of 6 from 56 to 338 C/My. The coo...
متن کاملMetallographic cooling rates and origin of IVA iron meteorites
We have determined the metallographic cooling rates for 13 IVA irons using the most recent and most accurate metallographic cooling rate model. Group IVA irons have cooling rates that vary from 6600 C/Myr at the low-Ni end of the group to 100 C/Myr at the high-Ni end of the group. This large cooling rate range is totally incompatible with cooling in a mantled core which should have a uniform co...
متن کاملThe metallographic cooling rate method revised: Application to iron meteorites and mesosiderites
A major revision of the current Saikumar and Goldstein (1988) cooling rate computer model for kamacite growth is presented. This revision incorporates a better fit to the ala + y phase boundary and to the y l a + y phase boundary particularly below the monotectoid temperature of 400 "C. A reevaluation of the latest diffusivities for the Fe-Ni system as a function of Ni and P content and tempera...
متن کاملCooling Rate Variations of Group Wa Iron Meteorites
Cooling rates of eight group IVA iron meteorites were determined using a modification of the Wood method where cooling rate curves are calculated as a function of central taenite Ni content and taenite half-width. The ma jor modification of the Wood method was to include the effect of? on the Ni solubility limits and Ni diffusion co efficients in the kamacite phase for each meteorite studied. T...
متن کاملRapid methods of determining cooling rates of iron and stony iron meteorites.
Two rapid and simple methods have been developed for determining the approximate cooling rates of iron and stony-iron meteorites in which kamacite formed by diffusion-controlled growth along planar fronts. The first method requires only measurements of the mean kamacite bandwidth and the bulk nickel content. The second method requires the determination of the nickel composition near the taenite...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Meteoritics & Planetary Science
سال: 2001
ISSN: 1086-9379,1945-5100
DOI: 10.1111/j.1945-5100.2001.tb01928.x